Gas piston operated firearm



Jam.v 37, i959 B. MAlLLARD GAS PIsToN OPERATED FIREARM Filed Feb. 13. 1948 A w m IN VE N TDR SERA/HR@ NAf/L Ffa,

@MM ATTURNEY Patented Jan. 17, 1950 UNITED s GAS rls'roN oPEnA'rED FIREARM Bernard Maillard, Geneva, Switzerland, assignor Y to Brevets Switzerland,

Application February 1 .In Luxemburg,

6 Claims.

The present invention relates to breech recoil operated firearms (this expression including both semi-automatic rearms, for which the gunner is to operate the trigger to iire every shot, and automatic rearms, firing by bursts, and of course firearms capable of working either semiautomatically or automatically) in which the energy necessary for actuating the breech is supplied by powder gases taken from the barrel of the arm and acting on reciprocating means for driving the breech rearwardly. The invention is more particularly applicable to small caliber firearms such as aircraft or anti-aircraft automatic guns, automatic or semi-automatic rifles, etc.

The object of this invention is to provide a firearm of this kind which is better adapted to meet the requirements of practice than those existing up to this time.

For this purpose, according to my invention, the movable breech system is actuated by means of at least one rodslidably guided in a bore provided in the mass of the firearm barrel, this rod having its rear end in` contact witha part of said breech system and its front end tted with a piston slidable in a cylinder and subjected to the action of the powder gases.

Other features of the invention will appear from the following detailed description of a preferred embodiment thereof with reference to the accompanying drawings, given merely by way of example, and in which:

Fig. 1 is a horizontal axial section of a portion of an automatic firearm according to the present invention;

Fig. 2 is a vertical axial section showing certain elements of the breech operating mechanism which are not visible on Fig. 1;

Fig. 3 is a transverse section on the line III- III of Fig. 2.

Concerning the general construction of this firearm, it includes, in the usual manner, at least one barrel l provided at the rear with a breech casing or receiver 2 assembled therewith for instance through a bayonet joint and in which can slide, parallel to the barrel axis, a movable breech system 3 operated as it will be hereinafter described.

The mechanism for operating breech system 3 includes at least one and preferably two reciproeating rods 4, preferably disposed symmetrically on either side of the axis of barrel i, each guided in a bore la provided in the mass of said barrel and subjected to the action of a return spring 5, the rear end of said rod acting directly on the Aero-Mecaniques S. A., a society of Switzerland 3, 1948, Serial No. 8,173

March 8, 1947 Geneva,

movable breech system 3 in a push-piece fashion,

whereas its front end includes a piston 6 slidable hoop 8 surrounding barrel I and fed with powder gas under pressure in a cylinder 1 provided in a from the inside of said barrel.

It will be readily understood operating the movable breech system 3 of easily detaching barrel l from breech casing 2 since the whole of this mechanism is carried by said barrel.

Further-more, as rods 4 act directly upon the' 3, without interposition: of push-pieces, the functional plays are reduced by said rods 4.

It will be advantageous to vsupply both cylinders 'l through'a common gas -tap 9, advantageously of adjustable necting the inside of barrel I with a transverse distribution conduit system l0, of semi-circular general shape, which supplies both of said cylinders.

It will be understood that such an arrangement, while localizing the gas tap 9 in the most favorable region of the barrel, makes it possible to distribute powder gas under the same pressure to both cylinders 1 and therefore to ensure the transmission of identical efforts to the two lateral portions of the breech system acted upon by the rear ends of rods 4.

It should be noted that it will be of interest slightly to incline rods 4 in the transverse direction so that they converge toward the rear and can thus act directly upon the movable breech system. Guiding of rods 4 then takes place along the rear portions of these rods.

Finally, in order to reduce the shock that might occur at the end of the recoil stroke of rods 4, each of them may be tted with shock absorbing means constituted, for instance, by a plurality of superposed elastic washers H interposed between the rear face o-f piston B and the front end of a sliding sleeve l2 bearing, through its other end, against return spring 5.

In a general manner, while I have, in the above description, disclosed what I deem to be practical and efficient embodiments of my invention, it I do not Wish to should be well understood that that, with such' `an arrangement, the above described mechanism for permits i the o horizontal plane passing through the axis of movable breech systhe latter is not-submitted to any upsetting torque when it is pushed rearwardlysection, located in the verf tical plane of symmetry of the rearm and conbreech system guided in said breech casing, said@ barrel being provided with at least one longitudinal bore, a rod having at least itswreareportion guided in said bore and its -rean end 1in... contact with the front part of said breechzsystemzrrethe front position of said system, a piston,car-riediley,l

the front end of said rod, anda cylindersurrounding said piston for cooperationtherewith Y and carried by said barrel, the front part"ofsaid cylinder being in of said barrel.

2cK? breeolr recoiLpperated-)flrearm `vvhichrcomprisesiain combinatin;, awbarrel, abreech casing atiafthef:rearcendfroffsaid-f barrel, v a reciprocating breechfgs-ystemszguided inasaid --breeclr casing, -said barrel being provided withttwol-longitudinal bores extendingffsynnnetrically.-.-oneither sidev of the alf-is;V oefsaid:barrel1,,y a rod-moving Aaiwleast i-tsrear portion;:guidedn`n.eachr offsaid, boresV and lits e rear endfimcontactwiththe. iront .part ,of saidbreech systemixinmthe irontipositiom thereof, a, piston carried by the front end of said rod, andeaicylindenfsurroundingsaidlpiston for cooperation .therewithfithe; front-,ipartfofe each. of :said-cylinders beingi oommunicationwwith the insideof said barrel.v

f3.rAA breech :recoil operated-mecum which comprises;v inycombination; abarrelpv a breechr casing atufthefi'reareend.. oirK fsaid fbarrel; af reciprocating 'breeclmsystemguidedfin said breech casing, said ba-nrelheing` provided .with twolongitudinal-'boresA extending in the horizontal plane passingthrough the-axisfofesa-breech systenn symmetrically on eithlenside of theaxis4 ofwsaidV barrel," a Yrod.-having at'fleastffitsf manfportionl;l guided-in each` ofA said bores-.1 and itssrear end` Yin contact-with the-front? communication with the'iinside.

part of said breech system in the front position thereof, a piston carried by the front end of said rod, and a cylinder surrounding said piston for cooperation therewith, the front part of each of 5 said cylinders being in communication with the inside of said barrel.

4. A.rearm.according .to claiminwhich the vertical planes of rsaid rods convergentoward the rear of the firearm, the guiding bores cooperating -lOv-With the rear portions of said rods.

5. A firearm according to claim 2 in whic said 5xbarrel-"isiprovided with a single outlet po t in ,communicatlonmithjhe front parts of bo of \saidgcyliderslfori'feeding powder gases thereto.

-fGalbreech'rrecoilppperated rearm which comprises, in combination, a barrel, a breech casing 'gat'therearieridibfwsaid barrel, a reciprocating --b're'elrisy'stem guided in said breech casing, said 'f fbarrelabeing provided with two longitudinal bores extending symmetricallyr on either side of the axisathereoga rod.having Aatleast. itsV rearportion guidedJn-.eachf orfl`saidl bores 4and, its.' reanlendiin contactwith theftrontpa'rtoi said 'breechsy'stem l inthe .frontrpbtionmhereof, alpiston `I carriedlxy the front endoisaid rod,.a' h`oop. surrounding said barrel,` anmacylinder surrounding saidpiston for cooperation. there-with.lhou'sedin said,A hoop, the frontfpartoiezch ofgsid cylinders being .in .communication ywith the ins'idei 0f` said. barrel.

Q'BERJNARD 4MILLARD.

`- REEERENcEsf CITED .iThe:vffollowing;`I references Aarefofl recordfin the" '35 UNITED sTATEs PATENTS s Number Name Date 960,825 ..ep11eoni. ;.iune 7,. 1910 1,006,487 Gii'etta Juiy, 1919,` I40 1,387,460 Beers ,.Aug..16, .1921 2,031,305 ;,Ena,et.a1..-- Fen-1a, 193s 2,196,852 ,Browning .Apn 9,; 1940 2,199,871 f Brengt m.May 7,` 1940 2,3411780 .Horan 1 creeis, 1944 2,345,736 

